Make sure the heat is set all the way to HOT.
Look for a bleed screw, near thermostat housing or highest point in cooling system, and open it and close it when only a full and steady stream of fluid comes out. DO NOT OPEN IT WHEN SYSTEM IS HOT. OPEN IT WHEN YOU FIRST START THE ENGINE. YOU CAN OPEN IT JUST A BIT TO START, BUT REMEMBER, THIS IS HOT AND UNDER PRESSURE.
Simply keeping the engine running can help to bleed the coolant system. Fill it until the thermostat opens.
Here is a link for bleeding fluid systems. Bleeding cooling systems is the second paragraph.
You might get an infra red thermostat as they are under $ 20 now and the thermostat should open at 176-183 degrees farenhiet.
October, 11, 2011 AT 6:54 PM
Power the radiator fan direct from the battery and see if it'll turn On if so next to check is the coolant temperature sensor, fan relay-last the computer. Remove the rad cap, Fill the radiator 1"in. From the opening-now find the bleed valve open it till coolant comes out-close the bleed valve-refill as needed -then start the car up till it reaches normal operating temperature and keep filling till it no longer will take it now put radiator cap on. Also check the reservoir tank make sure its filled to the proper mark-